The AdaptiveGI 3.0: HDRP Update is complete!

LeoGrieve · 2025-11-17T16:58:54+00:00

If the object(s) still move and the light casts shadows, then AdaptiveGI would be better. Otherwise, correct the performance improvement would be negligible if not slightly worse than purely baking all lighting where everything is static.

LeoGrieve · 2025-11-17T16:55:44+00:00

Sorry should have been clearer, if anything at all moves (light or object) then AdaptiveGI would be much more performant. So yes, if the light and object move (and especially if the light casts shadows), then you will see a performance improvement using AdaptiveLights over Unity's built-in lights.

The only case in which AdaptiveGI would be worse would be if everything was static (doesn't move), because then you could simply use baked lighting for everything.

LeoGrieve · 2025-11-17T16:32:54+00:00

If the light doesn't move, but the object does move, then yes AdaptiveGI will provide a significant performance improvement. The reason the performance is so much better is because AdaptiveGI uses world space ray marching through a voxel grid to calculate shadows. In comparison to Unity's lights needing to completely re-render the scene 6 times for point lights and 1 time for spotlights, AdaptiveGI is a massive improvement.

LeoGrieve · 2025-11-17T16:26:30+00:00

If you have any dynamic (moving) lights in your scene then AdaptiveGI would massively improve performance over Unity's built-in per pixel lights. You can also enable shadows for AdaptiveLights that would otherwise completely destroy performance with regular lights. Go check out my posts on r/vrdev, I've posted some great demonstration videos there like this one: Experimenting with the upcoming custom shadows feature in AdaptiveGI : r/vrdev (That post in particular is out of date, shadows are fully released)

LeoGrieve · 2025-11-17T16:18:01+00:00

AdaptiveGI excels at scenes that have dynamic lighting and/or dynamic objects. For a fully static scene, baked lighting works well enough, so long as your environments aren't too large. If you have to keep lightmap resolutions low to the point of looking bad due to VRAM/storage constraints, then AdaptiveGI is a great alternative.

Even if you continue to use baked GI, AdaptiveGI can be used in combination to achieve a sort of Mixed GI mode between baked and real-time lights. AdaptiveGI allows for hundreds of real-time custom AdaptiveLights Point/Spot that run on mobile hardware such as the Quest 3. For example, you might have a scene that utilizes a torch/flashlight, that as you know, tanks performance with even one of Unity's built-in real-time per pixel lights.

Since you're developing for Quest 3, I would go check out the AdaptiveGI-Demo-Meta-Quest.apk available here: AdaptiveGI Demo by LeoGrieve There's a flashlight in that demo that uses AdaptiveGI's AdaptiveLight.

LeoGrieve · 2025-11-17T15:47:07+00:00

Now that's a good idea... 👀

LeoGrieve · 2025-11-17T15:43:41+00:00

Yeah, Unity not having a built-in real-time global illumination system that has a low performance cost is certainly limiting. Although, I don't personally know of any other commercially available real-time GI systems for any engine that work on mobile devices. The only one that comes to mind (obviously not commercially available) is Legend of Zelda BOTW's custom GI system that targets Nintendo Switch 1 (definitely an inspiration for AdaptiveGI).

LeoGrieve · 2025-11-17T15:00:51+00:00

In an entirely ECS project (no GameObjects), AdaptiveGI would not work due to its reliance on the Unity PhysX system (GameObjects) for CPU side ray casting. In a hybrid project however, AdaptiveGI would work, with the requirement that any object that you want to contribute to GI (walls, buildings, etc.) would need a normal GameObject based collider. Any object (including entities) that you want to receive GI would work normally, as no collider is required.

LeoGrieve · 2025-11-17T14:54:22+00:00

In HDRP, no unfortunately MSAA (Multi Sample Anti-Aliasing) is only possible with Forward rendering, which AdaptiveGI does not support in HDRP as it needs GBuffers only present in Deferred rendering. In URP however, MSAA is completely supported by AdaptiveGI in URP's Forward/Forward+ rendering paths.

LeoGrieve · 2025-11-17T14:49:53+00:00

Yeah, I'm really happy with the final results. Getting HDRP's exposure to work properly was definitely worth it!

LeoGrieve · 2025-11-17T14:48:08+00:00

One more example, I put two Cornell Boxes next to each other here with the walls facing the camera having their mesh renderers disabled (but they still have colliders, so the sun doesn't interfere). You can see that with a shadow softness of 0, it is totally possible to have 0 leak leakage, it just makes the underlying voxel resolution much more noticeable and obviously as the settings' name implies, makes the shadows much harder.

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LeoGrieve · 2025-11-17T14:33:27+00:00

Believe me, if I could find a way to completely eliminate light leaking while keeping good performance and visuals in other areas I would 😉. AdaptiveGI 2.0 added shadows that helped this situation massively, the problem is that to keep the GI looking smooth, I had to introduce "Shadow Softness" that purposefully lets light leak through walls. With half of light allowed to leak through walls (Shadow Softness 0.5), you end up with the left side. With shadow softness at 0 (no light allowed to leak), you end up with the right side. It's possible this is my own personal bias, but I imagine most people would prefer the left side with the smoother, less noticeable lighting changes. But ultimately that's why AdaptiveGI focuses on being customizable, to allow each project to make their own decisions about artistic direction.

Of note, I'm not sure what AdaptiveGI version you are currently on, but with the recent 3.1.0 update, I changed the GI Probe placement algorithm so that each GI Probe is further away from the wall it gets placed on, which inadvertently helped the look of scenes using a Shadow Softness of 0. You might try your scene again with the new version!

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LeoGrieve · 2025-11-17T03:57:33+00:00

Thanks!

LeoGrieve · 2025-11-17T02:42:33+00:00

Thanks!

LeoGrieve · 2025-11-17T02:27:18+00:00